High impact information on gata5

• Previous studies have indicated that gata5, a zinc-finger transcription factor gene, is required for the development of the zebrafish gut tube [1].
• Here, we show that gata5 mutants also display defects in the development of other endodermal organs such as the liver, pancreas, thyroid and thymus. gata5 is expressed in the endodermal progenitors from late blastula stages, suggesting that it functions early during endoderm development [1].
• Conversely, overexpression of gata5 leads to expanded endodermal gene expression [1].
• These signals also induce the mesoderm-expressed transcription factor no tail (ntl), whose initial expression coincides with gata5 in the cells closest to the blastoderm margin, then spreads to encompass the germ ring [2].
• In embryos lacking both squint and cyclops, members of the nodal group of TGF-beta related molecules, gata5 expression in the blastoderm is abolished, making these factors primary candidates for the endogenous TGF-beta signal inducing gata5 [2].

Anatomical context of gata5

• We characterised a gene, zebrafish gata5, which is expressed in the endoderm from blastula stages and show that its transcription is induced by signals originating from the yolk cell [2].
• Expression of a fibroblast growth factor (eFGF) or a dominant negatively acting FGF receptor shows that ntl but not gata5 is regulated by FGF signalling, implying that this may be the relay signal leading to the spread of ntl expression [2].

Other interactions of gata5

• Studies of mutants with morphogenetic defects have indicated at least six genes that are essential for cardiac fusion and heart tube assembly, including casanova, bonnie and clyde, gata5, one-eyed pinhead, hand2, miles apart, and heart and soul [3].

References